Checkmk Werk 14384: Fix command injection in livestatus query headers

ID: 14384 Title: Fix command injection in livestatus query headers Component: Livestatus Level: 1 Class: Security fix Version: 2.2.0i1 Prior to this Werk it was possible to inject livestatus commands in Checkmk's livestatus wrapper and python API. Attackers could add additional commands in the AuthUser query header using newline characters. This allowed running arbitrary livestatus commands, including external commands to the core. The issue could only be exploited by attackers from localhost, where the tampered header could be injected in a request to graph data. We thank Stefan Schiller (SonarSource) for reporting this issue. <b>Affected Versions</b>: All currently supported versions are affected: 1.6, 2.0, and 2.1. <b>Mitigations</b>: Immediate mitigations are not available. <b>Indicators of Compromise</b>: Review the logs of Nagios / CMC for suspicious commands. <b>Vulnerability Management</b>: We have rated the issue with a CVSS Score of 6.8 (Medium) with the following CVSS vector: <tt>CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L</tt>. A CVE has been requested. <b>Changes</b>: This Werk adds sanitization for the AuthUser header field.